"Okay, yes, angst and bad stuff and yadda yadda yadda WHAT'S THIS ABOUT A TF GUN???"
We've gotten to see Pandora's good side over the course of this arc, but yeah, she totally could have explained everything on Magus's behalf to people who chould have helped him, and instead opted for a convoluted nonsense plan.
One that Magus has actually gotten to work, but still.
Amplifying emotions and trashing TF guns
I'm not going into it in the comic itself for the sake of pacing, but there's a lot of precision emotional amplifying Magus could have done to increase the odds of them settling on the dewitcher diamond plan. Feelings of urgency, that feeling one gets when they think they've come up with a good plan, etc.
Granted, that wouldn't work if it wasn't a plan they easily could've gone with anyway, so no one's exactly off the hook, here.
And now, the obvious question: "Was Magus part of your master plan back in 2002", and the answer: "No." Magus's involvement was decided on later, and his manipulation makes way more sense than any explanations I had in 2002 for Tedd zapping Elliot or the TF gun breaking.
I don't think the terrible dewitchery diamond plan needed any sort of explanation beyond "sometimes people have bad ideas", so my saying Magus was involved in that decision as some attempt to "fix" that. Given what his plans were, however, it would be weird if he just sat back after Elliot was zapped and was like "welp, that's that. I'm sure they'll decide on the solution I want. I don't need to do anything else."